Download Tree Diseases and disorders, Geauga Parks District, 2009

Woody Plant Diseases Observed within the Geauga Park District, With a listing of
The more common Tree and Shrub Species, Based on Observations made during
the spring, summer and fall of 2009
Performed by Dr. Samuel J. Mazzer under grant from the Geauga Park District, Geauga
County, Ohio. Submitted November 1, 2009.
Contact:
Samuel Mazzer
6181 Washington St.
Ravenna, OH 44266
(330) 677-5880
[email protected]
Mazzer—Geauga Park District tree disease study, 2009
Contents:
Part One: Overview—forest health issues observed, particularly Beech bark disease
and Armillaria infections. ................................................................................................. 4
Beech bark disease:................................................................................................. 4
Armillaria: .............................................................................................................. 6
Part Two: Dominant forest trees and shrubs of the Geauga Park District, and
major diseases observed or likely:................................................................................. 12
Pinopsida class: The conifers............................................................................... 12
Taxacae family: Yews.............................................................................. 12
Pinaceae family: Firs, hemlocks, tamaracks, pines, cedars and junipers. 13
The Genus Abies, The true Firs: ............................................................... 13
The Genus Tsuga, the Hemlocks: ............................................................. 13
Important diseases: ...................................................................... 13
The Genus Larix, The Tamaracks:............................................................ 14
Important diseases: ...................................................................... 14
Pinus genus: The Pines ............................................................................ 15
Important diseases: ...................................................................... 15
Picea genus: Spruces................................................................................ 16
Important diseases: ...................................................................... 17
Cupressaceae family: Cedars: .................................................................. 17
Important Diseases: ..................................................................... 18
Magnoliopsida class: The broad-leaved flowering plants .................................... 19
Salicaceae family: Willows and poplars .................................................. 19
Important diseases: ...................................................................... 20
Juglandaceae family: Walnuts, butternuts and hickories:......................... 20
Betulaceae family: Alders, hazel nuts, blue-beech, ironwood &............. 22
birch: ......................................................................................................... 22
Important diseases: ...................................................................... 23
Fagaceae family: Beech, oaks, and American chestnut:.......................... 24
Important diseases: ...................................................................... 24
The Genus Castanea: American Chestnut................................................ 28
Important diseases: ...................................................................... 28
The Family Ulmacae: Elms and hackberries. .......................................... 30
Important diseases: ...................................................................... 31
The family Moraceae: Mulberries and Osage Orange............................ 34
Magnoliaceae family: Magnolias and tuliptree......................................... 35
Lauraceae family: Sassafras and spicebush ............................................. 36
The Hamamelidaceae family: Witch-hazel.............................................. 36
The Platanaceae family: the sycamore or plane-tree ................................ 36
Important diseases: ...................................................................... 37
The Rosacae family: Crabapples, serviceberries, hawthorns, cherries, and
plums......................................................................................................... 37
Important diseases: ...................................................................... 38
Mazzer—Geauga Park District tree disease study, 2009
The Simaroubacae family (invasive): Genus Ailianthus--the Tree-ofHeaven ...................................................................................................... 38
The Aquifoliaceae family: The hollies .................................................... 39
Important diseases: ...................................................................... 39
The Aceraceae family: The Genus Acer, the Maples. ............................. 39
Important diseases: ...................................................................... 40
Hippocastanaceae family: Horse-chestnut and Ohio buckeye.................. 43
The Tiliacae family: The Basswood trees................................................ 43
The Nyssacae family: Nyssa sylvatica, known as Black-gum, Sour-Gum,
or Tupelo................................................................................................... 44
The Cornaceae family: The Dogwoods .................................................... 44
Important diseases: ...................................................................... 44
The Ericaceae family: Rhododendrons, Azaleas and Blueberries ........... 47
The Oleaceae family: White, green, and black Ash................................. 47
Important Diseases: ..................................................................... 48
Bignoniacae family: Northern catalpa and trumpet-creeper vine ............ 48
The Rubiacae family: Buttonbush ........................................................... 49
The Caprifoliaceae family: Honeysuckles, viburnums, and elderberries 49
Mazzer—Geauga Park District tree disease study, 2009
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Part One:
Overview—forest health issues observed, particularly Beech bark disease and
Armillaria infections.
Beech bark disease:
During the course of our present study several forest health issues, dealing with Plant
Diseases were observed which may require periodic monitoring. It is important to note
that the overall health of a forest ecosystem is often dependent upon on a balance
between a several environmental factors that are operating within that system during a
given time period. Often, seemingly small changes occur within a given forest system
that may later initiate a cascade of effects that would not otherwise have been expected.
This may, in fact, be the case with a new, slow moving forest tree disease that is just now
beginning to make itself known in the forests of northeastern Ohio. Including several
forest areas managed by the Geauga Park District. During several of our previous
examinations of forestry related studies in the Geauga Park District, we noted the arrival
of a minute, introduced scale insect that was just beginning to show up on Beech trees in
Northeastern Ohio. These minute, white tufts were already quite numerous on the grey
bark of many Beech trees within the Park (most notably, on the abundant Beech trees
within The Beartown Lakes Reservation). Unfortunately, the presence of this insect is
closely linked to the arrival of a pervasive new disease of American Beech trees that has
slowly spread into our area from the Northwestern corner of Pennsylvania.
This disease, called “Beech Bark Disease” is a slow moving forest disease that has only
recently become noticeable in our area. The presence of the insect responsible for the
spread of this disease is cause for concern. At present this insect is still at relatively at
moderately low densities over much of the Geauga Park District. But this situation is not
expected to last. This new disease is unlike several other plant diseases, in that it consists
of two components. The first component of the disease is the arrival of the introduced
scale insects that have already noted, Cryptococcus fagisuga, is the sap-sucking insect
that is responsible for making numerous tiny punctures in the bark of Beech trees in order
to feed. In so doing these insects create many tiny openings in the bark of otherwise
healthy trees. These punctures compromise the integrity of the bark by creating what are
referred to as “infection courts” by Forest Pathologists. These tiny openings become the
portals which enable either of two pathogenic fungi (that are closely associated with this
disease penetrate through the otherwise protective bark of these trees) where they initiate
a pathological infection of the trees (living) Phloem and inner bark as well as the newly
formed sapwood. The arrival of either of these fungi and the subsequent fungal infection
of these underlying, nutrient rich, phloem and sapwood tissues initiates the type of fungal
infections that characterize the Beech Bark Disease complex which has only recently
become established in Northeastern Ohio. These scale insects are responsible for
initiating the infection and rot of the under-lying phloem and sapwood tissues by
pathogenic fungi.
Mazzer—Geauga Park District tree disease study, 2009
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At the present time, we believe we are seeing only this initial stage of this disease, as
indicated by the presence of numerous scale insects, is already present in many of local
woodlands, but date, we have not yet been able to confirm the presence of either of the
two species of Nectria fungi associated with this disease. It should be noted that the bark
openings created by these scale insects are, however, like an open door to any number of
other saprophytic or pathogenic bacteria or fungi, which are certainly able to initiate
wood rots or other species of wood rotting organisms. Consequently, beech trees in our
area appear to be still in the early, or initial, stages of the outbreak of another major tree
disease for Ohio.
The completion of this disease triad, beside Beech trees and scale insects, requires the
addition of either of two species of Nectria fungi (either Nectria coccinea var. faginata,
or Nectria galligena). The arrival of either or both, of these pathogenic Nectria fungi,
would complete the requirements for Beech Bark Dise
Nectria galligena and these species already exist in our area. So this fungus has probably
existed at low levels, in this area for years. (But, to date, this species was involved
species, to date, have been associated with the formation of “Target Cankers” and/or
“Cat-facing Cankers” on other species of hardwoods).
Unfortunately, the large Beech trees in the park are far from safe. The large number of
scale insects are already present in our forests are ready far from safe. Fungi, if anything,
are opportunistic organisms, and any healthy Beech tree that has received thousands of
minute punctures through what would otherwise have been an impervious bark covering,
are seriously compromised. And for thousands of saprophytic and/or pathogenic bacteria
and/or fungi, these bark injuries were too good an opportunity to miss. Consequently, the
bark and underlying wood of many beech trees has already been infected with what may
include a host of fungi, bacteria, yeasts, etc. so it is miraculous
to these Beech trees (but perhaps not as numerous) as would be expected, had these trees
been, in fact damaged by “a Beech Bark Disease”. Nevertheless, when the main front this
disease passes through this area we expect a large percentage of the largest Beech trees
will be lost.
As stated above, we have not yet seen the characteristic, reddish-orange fruiting bodies of
either of the two species of Nectria fungi that are associated with Beech Bark Disease
within the boundaries of the Geauga Park District. This is not an unexpected finding in
regard to this disease. The USDA Forest Service typically reports the incidence of Beech
Bark Disease by mapping two separate fronts: The first indicating the presence of the
scale insects. The second graph indicating localities where Nectria fungi have been
observed. This is reasonable, because insect populations are capable of spreading much
more rapidly than fungal spores.
From our experience with this Disease in the Geauga Park District, we believe that in
many of the Parks Beech woodlands, scale insects are present and quite numerous. And
that a few of these woodlands probably do have some level of Nectria fungi. This seems
reasonable because scale insects are mobile, while the spores of Nectria fungi are
Mazzer—Geauga Park District tree disease study, 2009
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microscopic and have no innate means of motivation. (The spores of Nectria galligena,
which are slightly larger than those of most Nectria spp. usually, measure around 17.5-19
x 7-8 microns)
Our data indicates that we are still in an earlier stage of the current outbreak. This is
certainly understandable, since this disease is obviously very slow-moving! (Beech Bark
Disease has been in Ohio since 1985, and in those fourteen years it has only spread into
five northeastern Ohio Counties. Even more telling is the fact this disease has required
119 years to reach the northeast corner of Ohio, from the point where it was accidentally
released in Nova Scotia, Canada, in 1890). Even so, Beech Bark Disease is currently
present across the entire northern tier of Counties in Pennsylvania, and has entered the
northeastern corner of Ohio in its slow progression to the southwest.
At the present time, we believe we are still in an early stage of development of this
disease in Geauga County. Note, we have not yet observed any of the characteristic,
orange-brown, pin-head sized fruiting bodies of Nectria fungi in association with any of
the numerous scale insect infections we have examined, to date, on beech trees in the
Park District. Unfortunately, it will be just a matter of time, because one of the species of
pathogenic Nectria fungi associated with this disease is present in Geauga County, where
it is was seen in association with a different (non-Beech bark) Forest disease. It might
also be instructive to point out that any bark injury is a potential entry-way through which
disease organisms may find entry through the protective, non-living, outer bark layers.
As already mentioned, these scale insect damaged areas of bark also serve as “infection
courts” for any number fungi, bacteria, viruses or other potential plant pathogens. This is
already occurring and a number of Beech trees have already developed numerous areas of
rotting wood and a number of trees have already collapsed in Geauga County woodlands.
The numerous bark injuries created by Beech scale insects tend to be scattered all along
the tree trunk and on the major branches. As a result Beech trees with diseased bark and
internal decay often tend to come down in pieces during windstorms, often causing the
trunk to break, or shatter, well above the ground in a unique manner called “Beech Snap”.
Armillaria:
Unfortunately, as this Beech Bark Disease becomes more established, and more Beech
trees are injured, or killed, these trees are likely to set the stage for the activation and
spread of another forest disease. This disease is World-wide in scope, and is without
doubt, the most widespread of all wood rotting fungi. This disease is often simply called
“Armillaria root rot”. As a group, these fungi tend to degrade almost any type of wood
that comes in contact with the soil. These fungi are widespread in North America, and
are present in most other non-polar regions of the World, where they act in concert with
host of other species of fungi to eliminate fallen trees, and other woody materials. Mostly
by recycling them through decomposition and eventually returning the remains to the
Mazzer—Geauga Park District tree disease study, 2009
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forest soil. But a number of the species in this group of fungi, also act as forest pathogens
and then attack, kill and then decompose even living trees.
These fungi are known in the Forest Industries as “Shoestring Fungi”. A name that
relates to the numerous dull, black, shoestring-like mycelial strands that characterize
these fungi, and by which these fungi are able to spread through the ground, from rotting
stumps, or half-buried logs, to infect other sources of dead, dying or in some cases,
living, wood. The fungi in the genus Armillaria, represent a common, and very widely
distributed group of Fungi that may be found in virtually any wooded area world-wide.
They are Basidiomycete fungi and tend to function largely as saprophytes, but under
certain conditions many also function as pathogens. Armillaria fungi occur in both the
Northern and Southern Hemispheres and are present on all of the major land masses
(except Antarctica). In general, many of these fungi function as saprophytes, but may
become problematic when conditions such as follow timber harvest operations, severe
storm damage, insect defoliation or forest fires damage or weaken large numbers of
otherwise healthy woody plants. It is then that that these fungi tend to become more
numerous and may display their pathogenic capabilities.
If the bark is pulled back from an Armillaria-infected tree characteristic rhizomorphs
such as those in the below left photo may often be easily seen. The right photo shows
characteristic fruiting bodies of Armillaria mellea:
(Photo credits: Rhizomorphs--Fabio Stergulc, Università di Udine, Bugwood.org; A. mellea fruiting
bodies: Andrej Kunca, National Forest Centre - Slovakia, Bugwood.org)
Mazzer—Geauga Park District tree disease study, 2009
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Typical fruiting bodies of Amillaria ostoyae. This species was observed fruiting
abundantly during a public foray at Sunnyside Park in October, 2009:
(Photo credit: Wikipedia Commons, photographer name not listed, used under Creative Commons
license.)
Because an increase in dead trees is expected among Beech trees as a result of Beech
Bark Disease, it is probable that we will see a corresponding increase in the number of
Armillaria fungi as these mushrooms spread through the forest first as saprophytes, by
invading and decomposing not only the beech trees killed by this disease, and then, also
by attacking many additional trees weakened by the Beech Bark Disease complex.
In any forest situation, dead stumps and rotting logs create numerous sites where
Armillaria fungi have become established in deadwood, well before these fungi begin to
send out numerous rhizomorphs to infect nearby dead, weak (or in many cases injured,
but otherwise living trees). At the present time, nine species of Armillaria fungi are
known to belong to this disease complex in North America, with seven species known
from the Great Lakes Region. During the several years that we have studied various
plant groups within the Geauga Park District, we have identified five species of this
complex from the forests within the Geauga Park District. The 2009 season had been
relatively dry during the summer and early fall, when many of these fungi produce their
Mazzer—Geauga Park District tree disease study, 2009
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Basidiocarps, or fruiting bodies (mushrooms). And it is then, when these Basidiomycete
fungi may be most readily identified. Consequently, it may be possible that one or two
additional species Armillaria fungi may be found in this area, but it is unlikely that more
than a total of seven species exist in this part of Ohio.
Of the species that we have so far identified within the Geauga Park district, we have
recorded the following five species: Armillaria gallica, A. mellea, A. ostoyae, A. sinapina
and A. tabescens. Of these, only the first four are generally considered to be part of the
Armillaria Forest Disease complex in this part of Great Lakes region. Of these the third
species, A. ostoyae, is unique, because this is the only N. American species known to
produce enzymes that allow it to attack conifers, as well as hardwood trees (the majority
of Armillaria species decay only hardwoods). So the presence of Armillaria ostoyae,
means that coniferous trees are also potential targets for this group of fungi. The last
species listed, Armillaria tabescens, is considered by several mycologists to be only
weakly, if at all, pathogenic, and several researchers believe this species to be strictly
saprophytic, and as such, it would not be capable of attacking living trees.
In spite of the distinct forest disease capability of most of these fungi, it should be
remembered that one of the most important functions of all fungi is in the degradation of
complex carbohydrates, including lignin, and other resistant plant compounds.
Eventually reducing these chemical structures into humus and other simple compounds
that are then recycled into the soil as simple chemical forms and elements that may then
be re-used by plants as nutrients for forest regrowth.
A unique and unusual feature that characterizes at least some species of Armillaria fungi
is that newly exposed pieces of diseased wood (exposed by cutting into an area of active
decay) from a stump or logs being decayed by Armillaria fungi) will often glow in the
dark, emitting a distinct, pale green, phosphorescent glow (this glow is quite often bright
enough to read by). In the Southeastern United States, bioluminescence of this type is
often referred to as “Foxfire” by the residents living in those areas. Like many well
established parasites, these fungi may utilize a living host tree for extended periods of
time
By means of the rhizomorphs produced by these fungi, this group of fungi is able to
radiate outwards from established infection sites (diseased stump, dead logs, or tree roots,
etc.). Probably by following a gradient of some chemical emanating into the soil from
potential new food sources, in order to colonize other stumps and/or tree roots, that may
be located some distance away. In orchards, these fungi often follow a row of fruit trees,
killing one tree in a row after another, like a row of Dominos. By this tree to tree means
of spreading, a given species of Armillaria may, over time, spread out through a forest to
encompass very large areas. Several of the largest of these colonies have been found in
the Aspen woodlands of the Pacific Northwest, where they have been found to
encompass thousands of acres (consisting of genetically identical hyphae). Because of
this ability, some of these fungi have been called the world’s largest living organisms (by
this same phenomenon, they might also be called the oldest of living things). In addition
to being important pathogens of forest trees, at least one of these species has also been
Mazzer—Geauga Park District tree disease study, 2009
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shown to have the ability to parasitize other mushrooms. It is now believed that the
“abortive stage” of a common fall mushroom, Entoloma abortivum results from this
mushroom being parasitized by a species of Armillaria.
Unfortunately, wide-scale causes of tree mortality, such as the “Beech Bark Disease”
may soon begin to kill scattered beech trees within the Geauga Park System, where it is
likely to create large numbers of dead, and dying, beech trees. This, unfortunately, will
fuel a further spread of these Armillaria root rot fungi as well.
An additional group of trees that are presently under attack by Armillaria root rot fungi
are American, and Red elm trees. This is fortunate for the Armillaria fungus, because by
the time many of these young elm trees are attacked and killed by the Dutch elm disease
fungus, the elm trees were likely to have been rapidly growing, healthy young trees. Such
young, rapidly growing trees have usually accumulated relatively high carbohydrate
reserves in the sapwood and phloem tissues, as well as in the trunk and branches of these
trees.
Consequently, when these young healthy trees are infected and killed by the Dutch elm
disease fungus, the wood of these trees are likely to have relatively high carbohydrate
reserves present, stored in the wood. These reserves can then be readily used by the
Armillaria fungi as a rich source of reserve food. Consequently, we often find abundant
rhizomorphs on, around and radiating from the base of Dutch Elm disease-killed elm
trees. The Armillaria fungi are then, because of these rich food reserves, able to spread
out even more aggressively, to infect additional trees in the vicinity of these diseased
trees.
Unfortunately, many White and Green Ash trees are likely to succumb due to a similar
onslaught, brought about by the arrival of Ash Decline. This last disease, also known as
Ash Yellows, is spreading into Ohio, and this disease, in company with the invasion of
our forests by the Emerald Ash Borer (already known to be spreading well into Ohio). In
some areas, this increased Ash mortality is suggestive that Ash Decline may have already
reached our area. Additionally, because some ash trees were growing in low areas,
periods of soil saturation during wet years may have further weakened any White and/or
Green Ash trees due to root zone saturation and anoxia. Black Ash, a species much more
resistant to soil saturation is, unfortunately rare in our area. But all species of ash are
being killed by the Emerald Ash Borer. Consequently it appears that it will be only a
matter of time before these weakened ash trees are killed by borers and/or Ash yellows,
and will then be very be quickly colonized by one or more of the species of Armillaria
fungi already known to be present in this area.
Of the five Armillaria species listed above for the northeastern Ohio, it should be
remembered that one of the species is Armillaria ostoyae. This species is capable of
producing enzymes that will allow this fungus to establish itself on conifers, as well as on
hardwoods. Because of the presence of this fungus, conifers, as well as hardwood trees
will be subject to attack by same type of root and stump rots that are associated with the
hardwood trees in our area. Because of this fungus, periodic checks should also be made
Mazzer—Geauga Park District tree disease study, 2009
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for these fungi around the base of conifers in landscape plantings, as well as in pine
plantations within the park area. However, it should be noted that trees weakened or
injured in some way are far more likely to be attacked by Armillaria Fungi. Healthy,
vigorous trees, without obvious injuries are rarely attacked.
This ability of A. ostoyae to decay conifers should also be noted, because many of Ohio’s
Pine plantations were planted at spacing intervals suggested for timber stands, but were
not selectively thinned. As a result the trees in these plantations are now crowded, are
overstocked. These trees are now too close together, and in competition for available soil
nutrients, light, and water. This inadequacy of resources is now a stressor, leading to poor
tree health. And in natural systems, weakness tends to be fatal in regard to pathogenic
diseases and fungi. Many conifers are also planted in lawns and in the vicinity of
Buildings, where they may be growing in compacted soils, or where they may be injured
by “string trimmers”, lawn chemicals and/or lawn mowers. Such trees will often have
limited life spans and will eventually be attacked by parasitic, and or saprophytic fungi.
We have also found that many of these pine plantations are also being damaged by grape
vines. When grape vines grow into the forest plantation they have a tendency to
overgrow the forest trees in a roof-like manner. Such a grape vine covered forest often
accumulates very heavy snow loads in winter. The tremendous weight of this
accumulated snow often causes portions of the forest to collapse under the weight of this
snow. The damaged trees in these areas then become sites where Armillaria may become
established. Several of these “snow collapse areas” can be observed in conifer stands in
the general vicinity of Ansel’s Cave, at The West Woods park.
In Ohio, as noted above, conifer plantations were often planted with in-row and betweenrow spacing’s that anticipated periodic thinning cuts (often, at 30 year intervals). Under
such a timber harvest schedule, these stands would have been thinned on a regular basis
by harvesting a select number of trees at timed intervals, such as every third row at 30
years, then every second row at 60 years, and finally, the third and final row at 60 years.
[However whenever any timber cutting is done it is essential that these harvest cuttings
be planned only on the advice and guidance of a Licensed Ohio State Forester]. After the
third row is harvested, these stands may then be re-planted. Or, after the site had been
properly prepared, the land could be converted to some other purpose.
An alternative, sometimes used to create more picturesque plantings, or for the creation
of wildlife habitat, might be to plant the trees not at spaced intervals, in rows, but rather
as scattered clusters, with the individual trees spaced far enough apart so that competition
for light, moisture and soil nutrients is not likely to become limiting as the trees grow to
maturity. Such plantings also tend to have a somewhat more attractive, natural
appearance, especially when planted with mixtures of different conifer species that
includes several fruit and/or nut producing shrubs and possibly hardwood trees as well.
Unfortunately, many parts of Ohio now have an over abundance White Tailed Deer.
Populations of these animals are now so high in many areas that many new tree plantings
are doomed to failure. In many cases even when the young trees have been enclosed in
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tubes designed to “reduce” browse damage. Deer numbers at these levels are unhealthy
for the animals themselves. As some State Wildlife Manager’s may recall from several
past experiences from other states where deer numbers were allowed to climb to such
High levels, overall animal health has declined as has fawn survival, and increased
disease and parasite loads.
Part Two:
Dominant forest trees and shrubs of the Geauga Park District, and major diseases
observed or likely:
Pinopsida class: The conifers
Taxacae family: Yews
The Genus Taxus, the Yews:
Taxus canadensis, Canada Yew: This understory shrub, sometimes called “Ground
Hemlock”, is becoming increasingly rare in Ohio, especially over the last ten to fifteen
years. This has been largely due to over-browsing by White-tailed Deer during the
winter season. This species is a favored browse plant by White-Tailed Deer, which seem
to be little, if at all, affected by this plant’s virulent cardioglycoside toxins.
Unfortunately, many other mammals are severely or fatally poisoned by ingesting the
taxine alkaloids found in this plant, which are dangerously cardio-toxic on ingestion by
most mammalian species. In the past, when this plant was more common than at present,
it was sometimes responsible for significant losses of pets and livestock in rural Ohio.
This species was not seen in Geauga County during this study, but, until a few years ago,
a relatively healthy colony of this species was present along the margin of a sheer
sandstone cliff above Phelps Creek in Ashtabula County, Ohio. We examined this site
during the current study, and found that nearly all of the Taxus plants at this location now
show evidence of having been heavily browsed except for those few plants which have
branches extending outwards over the sheer cliff edge - well beyond the reach of the deer
standing on the cliff margin.
Our over abundant deer herds are also beginning to cause other problems in many parts
of Ohio. They have already driven many Spring Wildflowers to near extinction in many
parts of Ohio. Recently deer have also been entering suburban locations where they are
beginning to feed on ornamental vegetation and vegetable gardens in and near several
Ohio Cities. Deer are also destroying many of the herbaceous wildflowers and
understory shrubs and other vegetation in many Parks where hunting is not permitted.
Deer have even caused several automobile accidents far from any natural environments,
in such unexpected locations as on the Main Campus of Kent State University in the City
of Kent, Ohio.
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Two introduced species, the Japanese Yew, Taxus cuspidata, and the English Yew,
Taxus baccata, are also frequently planted in Ohio as ornamentals, in landscape
plantings, or around commercial buildings and homes in Geauga County. These plants
may gain some degree of protection from deer by surveillance of the property by the
owners, or possibly by household dogs. However, when these shrubs are planted in
domestic areas, it should be noted that the introduced Yew species are also very toxic,
and there is some evidence that they may be even more toxic to domestic mammals and
children than is our native species. It should be noted, that in areas frequented by Whitetailed deer both of these introduced plants are favored browse plants that are eaten as
readily as our native species.
Pinaceae family: Firs, hemlocks, tamaracks, pines, cedars and junipers
The Genus Abies, The true Firs:
Abies balsamea, Balsam Fir: The range of this species, in general, is essentially
confined to the Spruce-Fir (or Boreal Forests) of the Upper Great Lakes, and adjacent
Canada. With the exception of planted landscape trees, it is therefore unlikely that this
species would occur naturally in northeastern Ohio.
A mention of this species “as escaped into Mitchells Mill’s bog”, in Chardon Twp., was
reported by E. Lucy Braun (in 1961, in The Woody Plants of Ohio). However, we have
no recent information regarding the location of this site, or whether these trees are still
extant in the vicinity of Chardon, Ohio.
Balsam Fir is frequently grown as a Christmas tree in Geauga County, where this species,
or its southern variant, Fraser’s fir, Abies fraseri, are both highly prized Christmas trees.
The Genus Tsuga, the Hemlocks:
Tsuga canadensis, Eastern Hemlock: The range of this species in Ohio is generally
associated with the more densely forested eastern and central regions of Ohio, where it
tends to be associated with cool, shaded exposures of cliff-forming sandstone.
Moisture evaporating from these shaded cliff faces create a cooler, more humid, local
“northern microclimate”, where eastern hemlock trees are often found in association with
other species of the Hemlock-Hardwood Association, such as yellow birch. These same
moist sandstone ravines also frequently contain a number of unique ferns and mosses as
well as exceptionally large specimens of tulip tree, sugar maple and red oak (often left
uncut due to the difficulty of removing logs from these narrow ravines). In some of these
hemlock gorges, plants like native white pines, trailing-arbutus, and other species
normally associated with more northern plant associations may also be found as well.
Important diseases:
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Because of the scenic grandeur created by these stands of large hemlock trees, woodland
trails often wind through these shaded stands of large trees. Unfortunately, these same
trails can cause soil compaction that damage shallowly placed beech and hemlock roots
that pass under and/or near the surface of these foot trails. Repeated root injuries of this
type often results in the formation of “infection courts”, which can allow pathogenic
fungi, such as Armillaria ostoyae root rot fungi, to gain entrance into these trail side trees
roots.
The Genus Larix, The Tamaracks:
Larix laricina, Tamarack, or Eastern Larch: Only one species of this far northern/
high elevation genus of conifers extends into our area, where it is near the southeastern
limit of its range. The extreme southeastern limit of the range of Larix laricina in North
America extends eastward from Ohio, into a few sites at higher elevations to the east.
Only one species of Larix is native to Ohio but several European or Asian species are
occasionally planted in our area.
In Ohio, Tamarack trees are generally confined to acidic, Ombrotrophic sites like the
Sphagnum Bogs found in the vicinity of Lake Kelso, at the Burton Wetlands.
Paradoxically, Tamarack trees may also be found in the vicinity of cool, spring-fed,
locations known as Calcareous Fens, such as The J. Arthur Herrick Fen, in Portage
County. In both of these areas, Tamarack trees do quite well even though the upwelling
calcareous waters that characterize a Fen, are quite different from the acidic waters that
characterize Sphagnum Bogs.
Important diseases:
Among the important but infrequent causes of Tamarack or Larch decline in either area,
is defoliation of the tamarack trees by the Larch case bearer (a small case-bearing
caterpillar). In both of these areas, however, a more common cause is root anoxia, which
is associated with a rise in water level. Many bogs and fens are located in areas where
beaver dams can easily result in an increase in water level. In this regard it should be
noted that the roots of all trees tend develop at a specific zone, or level, within the
substrate where they are growing. When ground water levels go down, these functional
roots of the tree may dry out. On the other hand, if there is a rise in water level, these
same roots (and their associated mycorrhizal fungi) are soon flooded and the trees roots
(and the peat in which the trees roots as growing are soon inundated, and if these areas
remain anoxic for any length of time, the trees roots will die).
Because the mycorrhizal fungi associated with the tamaracks trees roots are also sensitive
to anoxia, the health of a stand of Tamarack trees can often be estimated from the number
of specimens, and species, of mycorrhizal fungi that can be found growing in association
with the roots of these trees. This mycorrhizal association is so closely associated with
the health of the trees, that the number of different species of mycorrhizal mushrooms,
and the count of mushroom basidiocarps found under these Tamarack trees, may be used
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as a rough indication of the overall health of the fungi (and by extrapolation, the health of
the tamarack trees) in given bog or fen environment. Because the roots of these trees are
so sensitive to changes in water level, it is often useful to drive a stake (with an attached
“Stream Gauge”) into an area of standing water in the vicinity of the best stand of
existing Tamaracks.
The purpose of this water gauge is to allow the water level in the vicinity of the trees to
be periodically monitored. Water levels fluctuations are especially important when these
changes are likely to be altered by beaver activity. In the event that a water level rise due
to beaver activity is suspected, steps should be taken to quickly remove any dam(s) or
other blockage that that is causing the abnormally high water levels, before the
Tamarack’s roots begin to die from lack of oxygen.
Pinus genus: The Pines
Ohio only has four Native species of Pines (White Pine, Pinus strobus, Virginia pine,
P. virginiana, Pitch pine, P. rigida, and the Yellow, or Shortleaf pine, P. echinata). In
addition to these species, a number of additional species have also been planted in Ohio,
often along roadways, etc. These plantings often include Pinus sylvestris, Scotch pine, P.
resinosa, Red pine, and Pinus nigra, Black pine. These trees have often been planted
for use as timber as well as
Pinus strobus, the White Pine:
This is the only five-needle, or “Haploxylon pine” that is native to Ohio (Haploxylon
pines are characterized by having a single vascular strand down the center of each
needle). All other native pines in Ohio are Diploxylon pines (pines that have two
vascular strands down the center of each needle). In Ohio, native Diploxylon pines tend
to be more common in the southern and southeastern parts of the state.
White pine (either alone, or with one or two central rows of Norway spruce) are
sometimes used in open, windy locations in Ohio for the construction of windbreaks,
either to block drifting snow and/or for the creation of wildlife habitat.
Important diseases:
White Pine Blister rust, Cronartium ribicola, this disease was at one time the most
important disease of White Pine in the Great Lakes Area, However, it is now rarely seen
in our area. This is because all White Pine seedlings now being supplied by nurseries in
the United States are selected for genetic resistant to this disease. Additionally, the
planting of the shrubs that once served as an alternate host for this fungus disease (i.e.,
Gooseberries and Currants) were for many years controlled by law (these laws are still in
affect in several northern states) where White Pine is (or was)an important timber tree.
(This law has since been canceled in many areas because White Pine seedlings available
from nurseries are now varieties resistant to this disease.
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Phaeolus schweinitzii, the “Dye-Maker’s fungus, or “Dyer’s Mazegill” is an important
root rot of White Pine. This fungus was noted at only two locations in the Geauga Park
District. Specimens of this fungus were seen at the Burton Wetlands, and in the vicinity
of two large, old growth White Pines at Eldon Russel Park. Several old 2008, specimens
of this fungus were found, but no fresh specimens of this species were observed during
2009.
Other commonly planted Ohio pines are Pinus resinosa, (Red Pine). This pine is often
called “Norway Pine”, even though it is a native North American species and an
important component of the Hemlock-Hardwood and Conifer Forests of the Upper Great
Lakes and adjacent Canada. Pinus sylvestris, (Scotch pine) a Eurasian species, is also
planted in Ohio where it is often used for Christmas Trees. In our area Pinus nigra,
(Black pine) another Eurasian species is also frequently planted. This species is
commonly called Austrian, or Black Pine. This species is often planted along secondary
highways, where it’s higher resistance to salt spray makes it a better choice than many of
the other pine species that grow well in Ohio. It should be noted that in our area, there are
two different species commonly called “Black pine”. This second black pine is Pinus
thunbergii, from East Asia, and generally originating from Japanese sources. A less
commonly planted in Ohio is Pinus banksiana, or Jack Pine, (specimens of this species
were observed along side of the parking area at the south end of Headwaters Park). This
species of pine is well adapted to dry, sandy soils. The natural range of Jack pine extends
across from the sand plains of North-Central Michigan and Central Wisconsin,
northwestward, from the upper Great Lakes Region, across Canada, to the Fairbanks,
Alaska area, where it often hybridizes with a closely related western species, Lodgepole
pine (Pinus contorta)
In general, the fungi associated pine trees in the Park area consisted almost exclusively of
symbiotic, mycorrhizal fungi, or simple saprophytic species growing on the decaying
pine needles beneath the forest canopy.
Picea genus: Spruces
The Northeastern American members of this northern group of conifers extend from the
Upper Great Lakes and adjacent Canada, southward and eastward, and then down the
Appalachian Mountains, into the highlands of the Southeast. In addition a number of
both native and non-native species in this genus have been planted extensively in the state
of Ohio for landscaping purposes. These trees, because of their sharp tipped needles are
less commonly used for Christmas trees than some other trees with round tipped needles.
Picea abies, Norway spruce, This is a widely distributed forest tree in the montane
forests of northwestern Europe that has been planted widely in Ohio. This species grows
well in our area, is relatively disease-free, and has the potential for attaining a moderately
large size. Because of this, it is frequently planted in the Great Lakes area for
landscaping purposes, or in plantations for timber production. In addition, because of the
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mature size of this tree, it is sometimes used to form the central row(s) or the “core” of
planted windbreaks, with two, or more, rows of white pine. Often with smaller fruit and
nut trees planted along the margins to provide additional wildlife food and cover.
Important diseases:
Picea pungens, Colorado blue spruce, this attractive conifer has been widely planted in
Ohio as a landscape tree around homes and in parks. Unfortunately, in recent years this
species has been shown to be susceptible to Cytospora canker, a needle disease that
causes the needles of the tree to first turn yellow, and then brown, before falling off.
Recently this disease seems to be more common in Ohio, and is often responsible for
defoliating several of the lower branches on the infected trees. This disease is somewhat
unusual in that it is primarily a problem for blue spruce trees planted outside of the
natural range of the species. Cytospora canker is generally not thought of as being much
of a problem in the Rocky Mountain Cordillera, and northward, into Alaska.
A more important disease of blue spruce in our area, and primarily in Christmas tree
plantings, is Rhizosphaera needle cast. This disease causes infected needles to turn
yellowish and then a purplish brown, before falling off, leaving the infected branches
bare.
Several other species of Picea, native to Eastern North America, include Black Spruce,
P. mariana. This species is common species in the acidic bogs of central and northern
Michigan, and becomes abundantly common in bogs and muskegs further north. White
Spruce, Picea glauca, is a spruce of the colder, Boreal Forest regions of the Upper Great
Lakes and adjacent Canada. But this species like Black Spruce, has probably not
occurred in Ohio since the post glacial warming period that followed the retreat of the
Wisconsin ice sheet, several thousand years ago. Red Spruce, Picea Rubens, is nearly
confined to the mountains of the northern Appalachians, and does not extend westward
into the Ohio area.
Cupressaceae family: Cedars:
Juniperus virginiana, Eastern Red Cedar, and Juniperus communis, var. depressa,
Common juniper, these rather prickly species have a rather scattered occurrence in the
State of Ohio. Under natural conditions, the presence either one or both of these juniper
species is generally indicative of calcareous soils. Generally these trees indicate that
limestone bedrock is at or near the surface or near, the soil surface, or that limestone
fragments are present in the soil. Soil moisture level may, on the other hand, be widely
divergent. In southern Michigan, both of these species may be found growing in
exceedingly dry, lime rich, sandy knolls called Juniper Savannas. In a similar manner,
these same two species can also be found growing on nearly saturated soils, in
association with Sphagnum mosses and Potentilla fruticosa, in spring-fed Calcareous
Fens. In both of these areas these Junipers show a strong tendency to be found in areas
containing relatively high levels of lime. However, both of these junipers may be planted
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and seem to be able to survive in landscape settings where they seem to be able to grow
normally in soils with only moderate calcium content.
It has been suggested that a large part of the tendency of White-tailed Deer to browse
Junipers leaves and branches (and the following species, Arbor Vitae) is for the relatively
high Calcium content in the leaves of these species, as much as for their caloric value.
Calcium is required during spring and summer, by lactating females, and by males, in the
summer and fall for antler growth.
In the Sleeping Bear National Lakeshore area (in Northwestern Lower Michigan) The
once abundant Juniperus communis var. depressa has now been exterminated over large
areas along the Lake Michigan shoreline by over- browsing by the overabundant Whitetailed Deer in these No Hunting zones.
Important Diseases:
The Genus Juniperus is commercially important not only because these trees are the
source of red cedar timber, but also because Junipers serve as the alternate host for
several pathogenic, and economically important, Parasitic Fungi, the Gymnosporangium
rusts. These rust fungi alternate between Junipers plants (during the spring and early
Summer) and several (mostly) rose family genera (during the Summer into the Fall
months). The “Cedar-Apple Rust” is an example of one of these important fungal
diseases. This disease has two hosts, and alternates between Cedar shrubs (spring and
early summer) and then infects Apples, Quince and Pears (during the summer and fall).
The presence of this fungus typically results in a major loss (as culls) of saleable fruit.
Other economically important diseases in this group infect quinces, while other rust
species infect a number of wild, and cultivated species of Hawthorns and flowering crab
apple trees, including many of the commercial cultivars that are held in nurseries for sale
as landscape plantings.
Thuja occidentalis, Northern white-cedar (or Arborvitae) unlike the sharp pointed
leaves of many conifers, the leaves of Arborvitae, or Northern White-cedar, are not
sharp-pointed, but have rounded tips and the leaves overlap, somewhat like miniature
shingles.
The common name for this tree, Arborvitae (“tree of life”) relates to the use of this plant
by Native American Indians (and by early North American Explorers) as a preventative,
to ward off the occurrence of “Scurvy” during winter. Scurvy is a potentially fatal disease
(of humans) associated with an inadequate dietary intake of Vitamin C. (Vitamin C is
common in green, living plants, but the green food plants that these early explorers were
familiar with, could not be grown during the winter, nor were they available on board the
ships of that era. The attempt by the British Navy to supply its sailors with Vitamin C,
was an acceptable plan, but the plan was a failure because the navy, in an attempt to
concentrate the lime juice they would issue to the ships crews, had been boiled to
concentrate it. Unfortunately, this process would only concentrate the citric acid content
of the lime juice. Vitamin C is destroyed by heating, so any attempt to concentrate lime
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juice by boiling would result instead in the loss of the vitamin C originally present in the
juice. Consequently, the lime juice served to the British seamen, often called “Limy’s”
(due to their habit of drinking this “concentrated” lime juice) were in fact receiving no
vitamin C at all, and continued to be sickened by scurvy.
Early European explorers in the new World soon discovered that American Indians were
not sickened by scurvy. And soon found that the Indians had been eating small amounts
of evergreen plants during winter. One of the few available green plants (that did not
have sharp points on their leaves) was Arbor vitae, this plant was indeed a “tree of life”
for many early explorers that ventured into these frozen northern forests of Canada and
the Northern United States.
Unfortunately, Ohio’s natural stands of Arborvitae, as well as both Juniper species, and
the Ground Hemlock, or Yew (Taxus canadensis) are being severely damaged, or
eliminated all together, by the browsing activities of the current overabundance of whitetailed deer. This problem is compounded over much of the former range of these plants
because Deer also recognize that these plants as a rich source of Calcium. (male deer
require additional Calcium for antler growth in spring and summer, and pregnant females
require extra Calcium during late winter and early Spring, and then, and then for lactation
from late spring through early fall).
This problem is now being compounded over much of the former range of these plants
because White-tailed Deer are now more abundant than the vegetation of these areas can
support, and these animals have learned to recognize these plants as a rich Calcium
sources and tend to eat inordinate amounts of these plants. Consequently, these plants are
often heavily browsed, often to extinction, when White-tailed Deer numbers become
excessive. Many northern cottage owners, on returning to their properties after the
winter’s snows have melted, often discover to their dismay that many of their evergreen
landscaping shrubs have disappeared with the snow.
Magnoliopsida class: The broad-leaved flowering plants
The class Magnoliopsida includes all broad leaved flowering plants, including all forest
trees that produce flowers instead of cones, and are characterized by the presence of
broad leaves, instead of the needle leaves characteristic of Conifers.
Salicaceae family: Willows and poplars
Some of the largest trees in the Great Lakes region are willows, where specimens of
Salix alba and Salix nigra have both been recorded with trunk exceeding nine feet in
diameter. Both of these trees are National Champions for their respective species. This
family includes two essentially shade intolerant genera: Salix, The willows, and Populus,
the Cottonwoods. The genus Salix contains both tree and shrub forming species,
including many species which have a tendency to grow in, or near water. The genus
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Populus is also shade intolerant, and contains trees that range from moderate to large in
size at maturity.
The genus Salix, in addition to large trees also contains a large number of smaller shrubforming species that often prove notoriously difficult to identify. Identification of willows
to species often requires material of both pistillate and staminate florets which, in some
species occur on separate plants.
Important diseases:
Relatively few diseases of willow are of major concern, other than Basidiomycete root
and stem root rots which tend to be associated with injuries.
The genus Populus, contains both native and introduced species, as well as a number of
Nursery-bred hybrids. This group of trees tends to be very intolerant of shade, and
several species (both native and introduced) appear to be susceptible to a number of leaf
stem and root diseases. Four species are native in Geauga County, including Populus
deltoides (Cottonwood), P. balsamifera (Balsam Poplar), P. grandidentata (Bigtooth
Aspen), and P. tremuloides (Quacking Aspen).
An introduced species, Populus alba, the European White Poplar has, has also been
planted in several Geauga County locations, seems somewhat more disease resistant than
most other introduced Poplars. It is also unique in that only female trees were introduced
into this country (this tree cannot spread by seed, but only by root cuttings or suckers, to
form new clones). The leaves of this tree are shiny and dark green above, while the
undersides of the leaves are white. Strong winds often turn the leaves of this tree
upwards by the wind, causing these trees to suddenly turn chalky-white when the
undersides of its leaves are suddenly exposed.
Several introduced Populus species and several Populus hybrids, have been introduced
into northeast Ohio. Several of these species and hybrids are also sensitive to several of
the same leaf and stem diseases that are found on our native species. This list includes
several “Hybrid Poplars” and also includes such species as the disease prone Populus
nigra var. italica or “Lombardy Poplar”, (This tree tends to have an exceptionally short
life span in our area due to a severe bark disease of this species, the Dothichiza Canker.
On the other hand, another introduced species, Populus alba, or the European White
There are a number of other important leaf, stem and root diseases that attack Poplars in
Ohio, including Venturia populina, Mycosphaerella populorum, Cryptodiaporthe
(Dothichiza) canker, Cytospora chrysosperma, Leucocytospora nivea, Cryptosphaeria
populina, Hypoxylon mammatum, and Ceratocystis fimbriata. In addition several
Basidiomycete fungi may enter the roots, stump or branches where injuries have created
infection courts for entry of these fungi into the trees trunk such as the relatively common
Dryads saddle, Polyporus squamosus.
Juglandaceae family: Walnuts, butternuts and hickories:
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The Genus Juglans: The Walnuts and Butternuts: This genus contains two treeforming genera that are native to our area, Black Walnut, Juglans nigra, and Butternut,
Juglans cinerea.
Of these, the Butternut is in severe decline, and is now rarely seen in Ohio. This decline
is due to an exotic canker disease, with an almost unbelievable name (Sirococcus
clavigigentijuglandacearum) that was apparently introduced into this Country from Asia,
in shipments of whole logs. Infected trees develop black, bleeding cankers and
eventually die. Trees infected and weakened by this disease may then be secondarily
attacked by Armillaria root rot fungi, further speeding their demise.
Black Walnut, in contrast, continues to be a valuable timber (and nut producing) tree that
can still be found in a number of locations in Ohio. Walnut is especially well adapted to
stream valleys and river bottoms (especially rich second bottomlands). Additionally, in
addition to walnut trees are being planted for timber, in some areas they are also being
used as a source of salable nuts.
The fungus, Nectria galligena is often responsible for forming “Target cankers” on the
trunks of black walnut trees and a host other trees as well, and when numerous, can
severely affect the value and utility of saw logs, for commercial purposes.
The Genus Carya: the Hickories: This genus contains two subgenera with six species
in Ohio: There are two subgenera Carya, the true hickories, and Apocarya, the pecans.
Hickories, in general, are trees that are characterized by their exceptionally hard, heavy,
close-grained, and exceptionally strong wood (Roald Amundson, the first man to reach
the South Pole, used skis made from Shagbark Hickory, that had been grown in the
United States).
The nuts produced by these trees are all edible by wildlife, but only shagbark hickory
nuts are gathered for human use in northern Ohio. Several Nursery selections of pecans
are sometimes planted in northern Ohio, but the nuts produced by these trees are
generally not nearly as large, or equal in quality, to those grown in the southeastern
States. The pecan hickory, Carya illinoensis, does occur in southern Ohio, but naturally
occurring trees of this species have been recorded from only Butler County.
Subgenus Carya: In our area this Subgenus includes C. glabra, Pignut Hickory, C.
laciniosa, Shellbark or Kingnut Hickory, C. ovalis, Pignut Hickory, C. ovata, Shagbark
Hickory and C. tomentosa, Mockernut Hickory. All of the hickories in this section are
characterized by the presence of shaggy bark, with the exception of the Mockernut
Hickory (sometimes referred to as “White”Hickory) in which the bark is much more
closely attached to the trunk, and somewhat resembling the bark of Bitternut hickory.
Subgenus Apocarya: The Pecans, and Bitternut Hickories. Of these two species, only
the Bitternut hickory, Carya cordiformis is common and widespread throughout most of
Ohio. In our area, it is a frequent component of our mesic woodlands and is also fairly
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common in some low-lying bottomland, in the rich soil along some of our stream valleys.
This species can easily be recognized by its bark, which is closely applied to the trunk. In
addition, the buds of this species are naked( not covered by overlapping bud scales) and
yellow-green in color. As implied by its name, the nuts of this species have a bitter taste.
Hickories are host to a number of wood rots and other disease organisms, most of which
enter the tree by way of injuries to the bark of twigs, branches and/or on the trunk of the
tree (i.e., through infection courts). One of the more common of these are “Target
Cankers” so called because these lesions appear as a series of concentric scars on the
trunks of several different tree Genera. In Hickory trees these target cankers are often
caused by trunk infections of a fungus that can occasionally be seen on the forest floor as
a saprophyte. This fungus has a goblet-shaped fruiting body which is the perfect, or
sexual stage of this parasite, which is an Ascomycete, it produces a dark, fleshy cup, or
goblet-shaped mushroom, which usually arises from a piece of a partially buried dead
branch, in the early spring. This fungus is named Urnula craterium.
Betulaceae family: Alders, hazel nuts, blue-beech, ironwood &
birch:
The genus Alnus: The Alders. Three species of Alder have been observed growing in
wet areas within the Geauga Park system. Alnus rugosa and A. serrulata were
occasionally seen at wet sites within the Park area. A third species, Alnus glutinosa (an
introduced European species) has been planted at a few locations in the area (i.e., around
the small lake at Swine Creek). These shrubs (or small trees of A. glutinosa) are able to
tolerate extended periods of soil saturation, or even year round periods of root inundation
and are well adapted for growth in wet areas along streams lake margins and shallow
pools.
The genus Betula: The Birches. The most common, native, tree-forming species of
Birch found in the Geauga County area is Betula allegheniensis, the Yellow Birch. The
twigs of this species have a pleasant wintergreen scent when damaged and are quite
common in some parts of the Park system, especially in the vicinity of outcropping
sandstone bedrock. The only other Birch tree that is fairly common in this area is Betula
nigra, this tree, the River Birch, is frequently planted in Geauga County because of its
attractive, pale tan-colored bark, but it is relatively uncommon within the Park itself.
Betula papyrifera, the Canoe Birch, is often reported as a native species for Lucas
County, Ohio. But these reports appear to be based on a single tree that was almost
certainly planted (see Allison Cusick: “Is Betula papyrifera Marsh, indigenous to Ohio”).
Betula pendula, the European White Birch, is somewhat similar to our native White
Birch, and is frequently planted as a landscape tree in Ohio. Consequently this species is
also slowly spreading into Ohio’s woodlands. This species is often mistaken for our
native White Birch. A third Birch tree with relatively white bark is the native Gray
Birch, Betula populifolia. The native range of this species is east of Ohio, this species
also has relatively white bark, and is superficially similar to Paper Birch, but this species,
in our area, tends to be associated with Sphagnum bogs, where it often grows alongside
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Tamarack trees. Other species of Betula found in Ohio are shrubs, or hybrids, that are
occasionally found in association with acidic bogs or calcareous fens. These small, shrubforming species were not observed in the Geauga County area during the current study,
but may be present in the shrub zone around acidic bogs that support the growth of
Sphagnum mosses.
Important diseases:
While diseases among birch trees were not observed to be a significant problem in this
study, some trees with “target cankers” were observed. These formations are caused the
tree’s annual attempts to produce healing growth over open wounds caused by Nectria
fungi. They occur in a number of tree species in the area. While Nectria fungi have long
been present, they did not in the past represent a significant threat to forest health in
Geagua County. However, as discussed elsewhere in this report, this fungus will almost
surely become a substantial threat to beech trees in the near future.
“Target canker” on yellow birch:
(Photo credit: Robert L. Anderson, USDA Forest Service, Bugwood.org)
The Genus Corylus: Hazelnuts.
Only two members of this genus occur in Ohio. Of these the Common Hazel, or
Hazelnut (Corylus americana ) is occasionally found in our area . The second species,
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the Beaked Hazel, Corylus cornuta, was not seen, and would be considered rare in
northeastern Ohio. Any specimens in this area would most likely be planted specimens.
The small nuts of both of our native Hazelnut species are quite attractive to many birds
and mammals, including Humans. For this reason, Hazelnut thickets have a tendency to
spread slowly due to heavy feeding pressure twigs and branches and on the annual nut
crop by White-tailed Deer, squirrels, rabbits and other small mammals. This genus is
represented in northern Ohio, by the Common Hazelnut, but shrubs of this species were
not observed within any of the Geauga Park District sites examined during the course of
this study.
Fagaceae family: Beech, oaks, and American chestnut:
The Genus Fagus: The American beech tree:
Important diseases:
The American beech tree, one of our most easily recognized trees, is, in our area, and
over parts of northeastern North America, is currently undergoing a synergistic attack by
an introduced Scale insect (Cryptococcus fagisuga =C. fagi) and by one, or in some
areas, two, pathogenic Ascomycete fungi (a native Ascomycete fungus, Nectria
galligena, and/or by a related, European species, Nectria coccinea var. faginata.
The arrival of this insect has made it possible for a new tree-killing disease complex to
spread into our North American forests. Nectria galligena is a native fungus species that
does occur in our in our forests, but generally as an inconspicuous and relatively
infrequent fungus, but this fungus promises to soon become a part of a major new Beech
Disease in our forests due to the arrival of an introduced Beech scale insect
(Cryptococcus fagisuga).
The exterior surfaces of all trees are protected by an impervious epidermal layer of
epidermal tissues (bark) which acting as a shield, prevent potentially pathogenic
organisms from penetrating into the living tissues beneath. In a woody plant, these
epidermal tissues (bark) typically consist of a dead, often suberized (cork-like) surface
layers, that tends to be quite impervious to entry by moisture, pathogenic fungi and/or
bacteria. Unfortunately, in the case of this new disease complex, large numbers of these
new, introduced scale insects produce a number of holes in this bark barrier (to feed on
the sap) and in so doing, create numerous holes through these (in Plant Pathology these
openings are referred to as “infection courts”) through which pathogenic fungi Nectria
galligena and/or Nectria coccinea var. faginata can then pass thru the trees protective
outer bark, to initiate active an infections in the living inner bark, and into the underlying
newly formed wood beneath.
One of the characteristics of beech bark disease is that the location of these fungal
infection sites are determined by the location of the feeding punctures that are made by
these introduced scale insects. Consequently, these fungal infections are associated with
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this disease are often scattered, often occurring at locations almost anywhere along the
main trunk, and/or along some of the trees larger limbs. In this regard beech bark disease
differs from many other forest tree diseases, which tend to be more common near the
base of the tree. (Especially those associated with Armillaria fungi.)
Consequently, trees affected by beech bark disease are typically weakened at a number of
locations by these areas of rotting wood. Unfortunately, these locations of weakened
wood are often present at several points along the tree trunk and/or along the trees larger
branches. Because of this patchwork of weakened rotting wood, Beech trees often
behave quite differently than normal trees during windstorms. Because the diseased
Beech trees contain a number of weak areas, these trees may suddenly break or begin to
shatter, at several different locations well above ground level. Often the weakened limbs
of these may shatter, with large limbs falling piece-meal over a wide area. This
characteristic (called “Beech Snap”) is likely to make hiking along forest paths in a
Beech forest extremely hazardous during windy weather.
Beech Bark diseased trees can be especially dangerous because these forest grown
specimens are often among the largest trees in the forest. The uncertain behavior in the
way diseased beech trees break up needs to be taken into account by anyone planning to
hike through mature forests containing large beech trees whenever appreciable winds are
blowing, or when stormy weather has been forecast for the time period one is likely to be
in the forest.
Distribution map showing spread of beech bark disease. The scale insect (dark red
zones) leads, and remains in the pink areas, in which Nectria species follow with largescale infection:
(Source: USDA Forest Service, 2005)
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Beech scale insects appear as white fuzzy spots on the tree bark:
Nectria fungus fruiting bodies later appear on infected trees:
(Photo credits: Above—Samuel Mazzer, 2009; below--Andrej Kunca, National Forest Centre - Slovakia,
Bugwood.org)
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Cankers often appear on infected trees (below left). Many infected trees break off wellabove ground level—a phenomenon known as “beech snap”:
Photo credits: Above left—USDA Forest Service - North Central Research Station Archive, USDA Forest
Service, Bugwood.org; above right and bottom—Joseph O'Brien, USDA Forest Service, Bugwood.org).
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The Genus Castanea: American Chestnut
Important diseases:
The American Chestnut, Castanea dentata, this tree was once a dominant hardwood in
the Hardwood Forest Zone of eastern North America. Unfortunately a virulent fungal
disease, the Chestnut Blight, Crypohnectria parasitica (previously known as: Endothia
parasitica) was apparently introduced into the New York City area around 1904,
probably on imported Chestnut wood originating in China or Japan, where this disease is
endemic, and where it still exists (but the species of chestnut trees native to those areas
appear to be quite resistant to the disease).
In Eastern North America, infected chestnut trees soon develop small orange-colored
pustules with sticky orange spores that were spread on the feet of perching birds as well
as insects. Consequently this disease was rapidly spread throughout the range of the
American chestnut throughout in eastern North America, with a near 100% loss of this
exceedingly valuable tree. Until around 15 to 20 years ago, a few trees could still be
found that had died back to ground level, but were still able to send up a few suckers
from the root crown. Unfortunately, these sprouts were also quickly diseased before they
lived long enough to produce nuts and were able to reproduce.
Since American chestnuts are now nearly extinct, the only photographs of infected
chestnuts found during this research were taken in the late 1950’s:
(Photo credits: Photographers unknown; images from personal collection of Samuel Mazzer.)
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Today, small seedlings of this species can still be found in the understory of some
hardwood forests, but, with few exceptions, these small seedlings are too small and
heavily shaded to make much in the way of annual growth. Because of this it will be
quite a few years before most of them will have a chance to produce nuts. However, I
have managed to a tree (about 8”dbh) in a mixed hardwood forest at West Branch State
Park that I am monitoring. This tree did produce a few nuts in 2008, but whether they
were fertile or not could not be determined because squirrels or other rodents opened
chestnut bur before I returned to the tree that autumn. Even so, there was a nut-shaped
cavity in one of the discarded husks under the tree suggesting that at least one of these
fallen husks may have contained a nut.
Small Chestnut trees ranging from three, to about seven feet tall, are not uncommon in
several upland forests in the northeastern Ohio area, but whether these trees will escape
disease (because of their low numbers and isolation) remains to be seen.
Because of the scarcity of trees of trees belonging to this genus in Ohio, spontaneous
interspecific hybrids are unlikely to be found in the State. However a number of selected
chestnut hybrids have been planted in Ohio, that were bred specifically for resistance to
chestnut blight (a number of these hybrids have been planted on strip-mined lands, with
favorable reports from some areas).
A second species of Castanea, C. pumila, (“Chinquapin”) is occasionally seen in Ohio,
but this species has been recorded only from sites along, or close to, the Ohio River.
However, because this species is much more common in the states that border the south
side of the Ohio River, it has been theorized that the few isolated localities for this
species on the Ohio side of the river are probably from chinkapin seeds that were
deposited on the Ohio side of the river, by Ohio River floodwaters.
The genus Quercus: The Oaks
This genus has been much more successful in avoiding severe losses due to introduced
diseases than have a number of other tree genera in Ohio. There are twenty one species
of Oak Trees currently recognized in the State of Ohio and fifteen interspecific Oak
hybrids in the State. At the present time the following oak trees may be found in
Northeastern Ohio: White oak, Scarlet oak, Bur oak, Pin Oak, Northern red oak, Black
oak, and possibly Chestnut oak (in a few locations).
With this many species of Oak trees in the State of Ohio, it would not be surprising for a
fairly high number of interspecific hybrid Oak trees to also occur in the state. The fact is,
is that, in general one typically has to devote a considerable amount of time searching to
find a hybrid Oak tree in Northeastern Ohio. This seems even more remarkable when one
realizes that the Oaks are wind pollinated trees and our oak forests typically contain a
number of distinctly different species of oak trees.
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In our area, Oak trees are characterized by two distinctly different mating types, or
subgenera: The subgenus Lepidobalanus, the White oaks, and the subgenus
Erythrobalanus, the Red oaks.
Within these two groups, there appear to be few genetic barriers preventing a genetic
cross between any two white oak trees. Because of this, two different species of the
Lepidobalanus group should be able to cross to produce a hybrid White Oak tree.
In a similar manner, any two Red Oak trees that belong to the subgenus Erythrobalanus
should also be able to cross. And any such cross would create a hybrid Red Oak tree.
However, even though such hybrids should be theoretically possible, finding examples of
such hybrid oak trees often requires a considerable amount of time searching.
Of the oak trees occurring within our area study only one hybrid, Quercus x leana, was
observed (this species, known as “Lea’s Oak”) is a natural hybrid between the shingle
oak, and the black oak. Interestingly, during this study, this specific hybrid was, in fact
seen several times (An excellent specimen of one of these trees can be found on the West
side of the KSU Golf Course, next to Powdermill Road, in Kent, Ohio).
But we did not see examples of any other hybrid oaks, during this study.
The Family Ulmacae: Elms and hackberries.
The genus Ulmus: The Elms: Of the three Elms native to northern Ohio, only two
species are likely to be seen in Geauga County, Ulmus americana, the American elm and
Ulmus rubra, the Red, or Slippery elm. A third native elm species, Ulmus thomasi,
Rock elm, is rare in Ohio, and is now rarely seen.
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Important diseases:
Native elms in the United States have, like our native Chestnuts, been devastated by
introduced tree diseases—first by the elm phloem necrosis virus, and more recently, by
an even more devastating fungal infection, Dutch elm disease.
A photo from the 1970s illustrates the long-gone site of numerous and healthy mature
American elms. The species was an ideal urban street tree, and was also an abundant
native forest species:
(Photo credit: Joseph O'Brien, USDA Forest Service, Bugwood.org)
Several additional, non-native and rather “weedy”species of elm have often been planted
as windbreaks, or as street trees. Unfortunately, a small-leaved tree, the Siberian elm,
Ulmus pumila, is sometimes sold by Nurseries (as a substitute for the much more
desirable “Chinese elm”, Ulmus parvifolia ). The Siberian elm is an undesirable tree. It
is very fast growing, and is often planted as a “landscape tree”. Unfortunately, Siberian
elm, is subject to limb breakage in storms, and when injured often develops bacteria and
fungal infections that eventually become wet, weeping areas, that are frequented by
numerous Bacteria, yeasts and other fungi. These weeping, slimy areas are referred to as
a “slime flux” and the presence of these weeping, insect infested areas make the affected
trees unsightly.
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Slime flux growing on U. pumila:
(Photo credit: Samuel Mazzer, 2009)
Unfortunately, poor quarantine capabilities allowed a much more devastating disease into
North America. This is the insect-vectored, and fatal fungus disease of elm trees, “Dutch
elm disease” that was accidently introduced into North America, and has now spread
rapidly across the native range of elm in the United States. Unfortunately, like so many
tree diseases and forest insects this disease was not effectively quarantined (“too little and
too late”). Since it arrival in North America, this disease has led to a severe depletion of
elm trees in North America. This disease is vectored by two species of elm bark beetles
(the native elm bark beetle, and the introduced, European elm bark beetle). From the
examination of the egg galleries, and the larval tunnels made by these insects (both of
which may be easily observed between the innermost bark layer, and the outer surface of
the wooden trunk of dead elm trees) the excavated tunnels created by these beetles and
their larvae can be easily examined (the difference is between the central egg laying
gallery of the American elm bark beetle tends to be oriented with the wood grain (i.e.
vertically), while the European elm bark beetle’s egg-laying gallery tend to be oriented
horizontally (typically across the grain of the wood). The larval tunnels of both species
then radiate outwards from these central egg-laying galleries. Since both types of egg
galleries are common in this area, it is clear that both species of bark beetles were, and
continue to be, active in vectoring the Dutch elm disease in Geauga County.
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Egg gallery of native elm bark beetle, on twig:
(Photo credit: William M. Brown Jr., Bugwood.org)
Because American elm trees tend to flower and set seed on relatively young trees,
Sapling stands of these young elm trees are often able to set seed several years before the
trees become large enough to interest the adult bark beetles that vector this disease. This
is because the vectors of this disease prefer to feed on larger trees. This behavior tends to
allow seedling/sapling stands of young elm stands to continue to grow and to produce
viable seed for some time before becoming infected by this disease. Consequently, it is
likely that we will continue to see thickets of young, seedling/sapling stands of diseasefree elm trees for some time to come.
The genus Celtis: the Hackberries: The Hackberries differ markedly from the elms in
Ohio by producing fleshy fruits, which are quite unlike the dry, wind-borne samaras,
which are characteristic of our native elms. Only two species of Hackberry trees are
recorded for the State of Ohio. But because both of these species prefer somewhat
calcareous soils, neither species would be expected in Geauga County. The Common
Hackberry, Celtis occidentalis, is more widely distributed through Ohio, except for the
relatively lime-poor regions in the northeastern corner of the state (an area that includes
most of Geauga County).
The Dwarf Hackberry, Celtis tenuifolia, is found in only a few locations in Ohio and
native populations are limited to a few small areas in Highland and Adams Counties in
southwestern Ohio. No collections of this species are known from northeastern Ohio.
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The family Moraceae: Mulberries and Osage Orange
In our area, there are two species, the Red Mulberry, Morus rubra , and the “White”
Mulberry, Morus alba (note: some variants of this species have red fruits as well). Both
of these trees are largely spread by the birds that are attracted to the abundant, sweet juicy
fruits (multiple drupes) of these trees. Although the wood of these trees is rather soft and
weak, it tends to be quite rot resistant, and is often used for fence posts. The fruits of
these trees tend to be rather bland to an adults taste, but children seem to enjoy them
nearly as much as the birds do.
The Paper Mulberry, Broussonetia papyrifera, is not winter hardy in northern Ohio, it
has been planted, and reported occasionally, but this species is unlikely to survive except
in the southern-most part of the state and even there it would probably “winter-kill” to the
ground line during any typical Northern Ohio Winter.
The Osage-orange, Maclura pomifera , is a species that occurs rather infrequently in
Northeastern Ohio, where its presence is probably due to having been planted by man.
The tree is unique, in that it probably is the strongest, heaviest, and most rot resistant
wood native to North America. It has a “shear-strength” (a measure of wood strength)
that is approximately 2.5 times that of well seasoned white oak. It is also interesting to
note that the wood of Osage-orange is so heavy that it readily sinks when placed in water.
Historically, this was the wood used by the Osage Indians for the construction of their
very powerful bows. It was also used by them as a source of a yellow dye.
The unusual grapefruit-sized fruits of this tree present a rather puzzling question, because
none of our native mammals seem to have much, if any interest, in eating them.
Consequently, one wonders about the evolutionary development of a seed dispersal
mechanism for this tree. Some evolutionary botanists have theorized that a long-dead
member of North America’s Prehistoric megafauna (i.e., the Giant Ground Sloth) may
have been the seed vector for this tree, by eating and dispersed the seed of this tree. This
is because large fleshy fruits tend to be adapted to only one, a few species of Mammals.
Certainly, in several in several experiments where these large fruits were presented to
several large North American mammals (Moose, Elk, Bear) that existed in the native
range of this tree none of these experimental animals showed an interested in eating the
large fruits produced by this species. If, in fact, this plant was dispersed by a now extinct
member of Ohio’s megafauna, such as a Mastodon, or Mammoth, this tree may be, in a
way thought of as being a living fossil as well.
Pioneers occasionally utilized the spiny nature of this tree for the creation of virtually
impenetrable living fences for confining livestock. But today’s landowners seem to have
little interest in creating Osage-orange fences on modern farms. A number of years ago I
found an overgrown remnant of one of these fences in southwestern Michigan. The fence
had once been along a farm boundary and had been created by planting a row of Osageorange seedlings about three or four feet apart. The young saplings had then been cut off
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about knee high, causing the young saplings to send out a number of side shoots. These
shoots grew out in all directions, but only those shoots oriented in the direction of the
fence were allowed to remain, while the remaining stems had been trimmed off. This
operation probably took several seasons to complete but did, in fact, create a nearly
impenetrable barrier. Such a fence probably functioned much like a barbed wire (too
dense and painful to go through, and too tall for any attempt to climb over).
This tree was also grown in small groves for the production of fence posts, in a manner
similar to the small wood lots of Black locust that were also grown for much the same
purpose. However, Osage Orange is even stronger and more rot resistant than the Black
Locust.
Magnoliaceae family: Magnolias and tuliptree.
The Tuliptree and the Magnolias are among the most ancient of the forest trees found in
North America. These trees like the Azaleas and Rhododendrons these trees are of
ancient lineage, and also occur in the Himalayan Mountains of India and through parts of
Southeast Asia. The Tuliptree is the both the tallest, and most massive of the hardwood
trees of North America, sometimes growing to heights in excess of 200 feet and attaining
trunk diameters of 8 -10 ft or more ( there is a sawn-off stump at Thomas Jefferson’s
home (Monticello) that exceeds even this large diameter. Interestingly, Tuliptrees for
some, (as yet unexplained reason, other than the fact that these trees are often the tallest
objects in the forest) seem to have a propensity for being struck by lightning. (In this
regard, it is interesting that all of the very large Tuliptrees on the grounds of Monticello
(as a safety feature) have been fitted with lightning rods!). Because of this tendency,
should one find themselves in a forest during a thunderstorm, it would be wise to seek
shelter under a smaller tree of some other species.
Magnolia genus: The Magnolias
Of the Magnolias, only one species of Magnolia grows large enough to be considered a
tree, in Northeastern Ohio. This species, Magnolia acuminata, is commonly called The
Cucumber Magnolia or “Cucumber tree” (from a fancied resemblance of the green seed
pod of this tree to a cucumber). Like the Tuliptree, the Cucumber Magnolia is also an
ancient tree, and perhaps for this reason, it tends to have few natural enemies or diseases.
Other Magnolias are found in other parts of the Southeastern United States, but tend to be
considerably smaller than this species.
Liriodendron genus: The Tuliptree
Liriodendron tulipifera, is monotypic, and has an interesting disjunct distribution, being
found only in Southeastern North America, and in Southeastern Asia. Like the related
tree, the Cucumber Magnolia, this tree has relatively few natural enemies. Although
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Nectria fungi sometimes grow in some bark injuries on these trees, these Nectria
infections tend to be self limiting, and are generally too few in number to constitute a
disease problem.
Lauraceae family: Sassafras and spicebush
Ordinarily, Sassafras trees tend to occur in groups. These groups are probably of clonal
origin, and are often present along some roadside locations within the Park. Because
many of these trees were relatively young, the majority of these trees appear to be quite
healthy. However, in some areas, older trees in some more mature forest areas have a
few trees that show the characteristic “Target Cankers” that are generally caused by bark
injuries that have become infected by Nectria galligena fungi. The concentric rings are
formed each spring as the tree attempts to grow over and compartmentalize these bark
injuries. Unfortunately, in the case of these target cankers, the fungus infections are not
eliminated, and these bark overgrowths are repeated annually, eventually creating these
target-like bark rings.
A Ganoderma lucidum root rot was seen at the root collar of one injured sassafras tree,
but this disease is generally associated with older, usually injured tree.
Lindera benzoin, or Spicebush shrubs are among the first woody plants to bloom each
spring, and their yellow blossoms soon outline the wetlands, seeps, and other areas of
damp soil in low areas. No noteworthy Plant diseases were observed in association with
this plant.
The Hamamelidaceae family: Witch-hazel
In our area, this medium sized to large shrub is in a way the inverse of the Spice bush,
because as the Spicebush is found in low, wet areas, and is among the first to bloom in
the spring. Witch-hazel on the other hand is often found in the understory of dry, upland
oak forests, and is the last shrub to bloom in autumn, sometimes even retaining a few
flowers until the first snows of winter. Although this shrub once provided a liniment
(when mixed with whiskey or rubbing alcohol) for sore muscles, this liniment is now
used much less frequently. Other than for a few cone-shaped galls on its leaves, this
shrub seems little affected by insects or disease.
The Platanaceae family: the sycamore or plane-tree
In North America, during the pioneer era, trees of the sycamore species easily had the
largest diameters of all North American hardwood trees. Probably the largest of these
trees had a trunk with a d.b.h. measurement of 42 feet, 7inches. This tree was in Daviess
County, Indiana. The largest Sycamore recorded for Pickaway County, Ohio, had a
d.b.h. measurement of 32 feet, 10 inches, which is the Ohio record. These trees follow
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along the river bottoms throughout most of the state, but occasionally, in the nonglaciated areas, Sycamore trees are sometimes seen ascending the side of a valley. These
sites identify locations where seeps from water-bearing sedimentary rock are located
above layers of clay-rich, impervious shale, or coal seams. Where these seepage areas
occur, the slopes below are kept moist by these areas of surfacing groundwater. Allowing
water-loving plants like the Sycamore to ascend the sides of slopes that would otherwise
be too dry for this species.
Important diseases:
In general, Sycamore anthracnose is the most common defoliating disease of Sycamore
during Spring Season, especially during especially when cool and damp weather occurs
for extended periods. The conidia of this leaf blight disease (Apiognomonia veneta), is
spread during wet cool springs, and at times, can cause nearly defoliation of Sycamore
trees growing in lowland sites along streams and river bottoms.
The Rosacae family: Crabapples, serviceberries, hawthorns, cherries, and plums.
Taxonomically, the members of this family can sometimes be exceedingly difficult to
determine. This is because many of these “taxa” are not true species at all, but is instead,
self propagating “hybrids” that produce seed by an interesting apomictic means by a
process referred to as nucellar embryony (a type of natural, asexual cloning).
Apomictic plants are essentially hybrids, but because of their unique genetic condition,
they are able to produce seed (asexually) that are carbon-copies of the parent plant.
Consequently even though these Apomictic plants arise by cross pollination, producing
what would normally be a “sterile hybrid”, these hybrids are able to perpetuate
themselves by an interesting process called “nucellar embryony” in which a part of the
parent plant, the nucellus, grows into what would have otherwise been an abortive, sterile
seed. Such plants produce normal looking flowers and “seeds”. But the “seed” produced
by these plants grow into plants that are not only genetically identical to each other, but
are also genetically identical to their (single) parents DNA (i.e., they are genetically
identical clones).
This Family contains trees, shrubs, brambles and herbaceous species. Many of which
have spiny or thorny surfaces, as a means of reducing herbivory. This is a large family,
with of both native and introduced species, including high numbers of apomicts in certain
genera. Interestingly, this group of plants includes a number of taxonomically difficult
apomictic “species,” especially among the wild crab apples, serviceberries and the many
“blackberries.”
The Leguminosae family: Honey-locust, black locust, and redbud
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The members of this family are characterized by their bean-like flowers and typical
“bean-pod” shaped seed capsules. Some of the temperate species like the Honey Locust
produce large branched thorns along the trunk and on the larger branches that would
effectively prevent larger animals from ascending the trunk. The other common tree in
our area is the Black locust, Robinia pseudoaccaia. Earlier in our history, this tree was
often planted in small groves on family farms for a ready supply of fence posts, because
the wood of this species is very rot-resistant. This species also has an interesting adaption
against herbivory, in that the young stems have a pair of sharp spines at base of each leaf.
Later, as the shrubs grow larger, these spines tend to be smaller in relation to how high
these twigs are above the ground. This appears to be an obvious adaptation against
herbivory, as deer and other herbivores would not be able to reach the higher branches.
Important diseases:
The wood of this species is quite rot resistant and quite strong, (but not as strong, or rot
resistant, as Osage-orange). Relatively few insects or diseases trouble this plant in its
early years, but mature trees are affected by the Black Locust Borer, whose larvae tunnel
into the wood, creating infection courts, which then allow entry into the heartwood of
these trees by two important wood rot fungi that attack this tree, Phellinus rimosus,
(which has a upper surface that is cracked and nearly black in color, with a warm-leather
brown poroid surface below, the second fungus is Perenniporia robiniphila, which has a
pale, creamy-buff color overall. Both of these heart rot fungi severely weaken these
trees, eventually resulting in breakage and/or wind throw of these trees during
windstorms.
The Simaroubacae family (invasive): Genus Ailianthus--the Tree-of-Heaven
Luckily, relatively few trees belonging to this species have become established within the
Geauga Park System. And any that have, should from our experience, be marked for
elimination when found. We are aware of several scenic overlooks in Michigan other
Park areas that were (as recently as15 years ago) then just beginning to be invaded by this
non-native tree. Unfortunately, many of those sites are no longer overlooks. When I
revisited these sites last summer, I found the view from these hilltop locations (which at
one time had an unobstructed view of from 10 to 15 miles) was blocked, and the road to
these sites no longer drivable, because of the rampant growth of this species).
In addition to the weed-like growth of this species, there are other negative features
associated with this plant, the male flowers of this tree (the sexes are on separate trees)
produce a strong, nauseating odor during the Spring bloom period, and the female trees
produce large numbers of wind-borne seed that are spread widely.
From our observations, and from the reports of other States, this species should be
classified as an undesirable species. This plant should be marked for removal wherever
found on public lands, preferably before the plants have grown large enough to produce
additional seed and spread.
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The Aquifoliaceae family: The hollies
Only one species of holly is likely to occur naturally in our area, this species, Ilex
verticillata, (“winterberry”). Ilex opaca, American holly, grows in the hilly woodlands of
southern Ohio, but becomes more abundant further south, into Kentucky and West
Virginia.. Winterberry, grows to between six and ten feet in height, and is most common
in wet woods and/or the shrubby bog margins along the outer margins, and boggy
lowlands associated with Lake Kelso in The Burton Wetlands. In our area, it is most
easily recognized by the presence of its bright red drupes, which are often produced in
great number. These fruits apparently contain some substance that deters birds from
eating the fruits until winter is nearly half over, when they then begin to eat these fruits in
quantity.
Important diseases:
This plant is relatively disease free, but its leaves are sometimes affected by a “Tar spot
Disease” Rhytisma concavum, which is very obvious when present, because the leaves
appear to have had coal black tar dripped over them.
The Aceraceae family: The Genus Acer, the Maples.
Maples trees tend to be represented across a wide range of Ohio’s forest lands. Maples
extend from some of our driest uplands, down slope through some of the more mesic
mid-slope forests, and into to the rich bottomlands where some of its species are
frequently associated with the rich alluvial soils of the first and second bottoms along
riverine valleys. The sometimes saturated soils of some river floodplains are often
dominated large numbers of Box elder (Acer negundo), and/or Silver maple (Acer
saccharinum), and Red maple (Acer rubrum) (which has a broad range of potential
habitats) along with Sycamore, Basswood, Pinoak, and elm. The slightly higher sites
along some second bottoms often support stands of the Black Maple (Acer nigrum),
which some maple sugar producers claim even betters the sugar yield of the closely
related and more frequently used Sugar Maple (Acer saccharum). Like American Beech,
Sugar maples continues well up the higher slopes as well, where it may be controlled
more by soil nutrients than by soil moisture. Paradoxically, red maple is somewhat of a
“vagabond” that can be found from riverbank locations into well-drained upper slope Oak
forests as well, where lumbermen consider it an undesirable competitor to the much
higher quality upland hardwoods like the red, white, and black oaks that grow of these
often sandy upland sites.
Maple seed crops represent an important food source for a number of small mammals and
birds. These seed are important to wildlife because they are produced intervals through
the year, instead of all at one time. The earliest maple to produce a significant seed crop
is the Silver Maple, which drops its seed in late May-early June. The second is the Red
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Maple. There is then a hiatus, until the Sugar and Black maples drop their samaras in late
September into October, with some seed falling with the leaves in autumn. Box elder
trees are unique, in regard to our maples, in that their samaras remain attached to the tree
Well after other leaves fall and, in fact are often retained well into the winter season until
they are eaten by perching birds or small mammals (or until they are torn from their
pedicels by strong winter winds, to be skated over the snow to new locations possibly
hundreds of yards downwind. Because Box elder seed are not shed like other Maple
seed, but retained on the tree well into the winter, the seed of this tree often becomes a
significant source of winter food for some birds like the Evening Grosbeak, which
sometimes feed heavily on the seed of this tree well into the winter season.
Important diseases:
Diseases associated with our native maple trees are, for the most part, rather unimportant
leaf diseases and several wood rots that attack the roots, and/or the trunks of these trees
after the protective bark of the tree has been injured by storms, or damaged by
Lawnmowers, or other mechanical devices that damage the bark of the tree.
Several of the diseases that attack Maples inter the trees through bark injuries. These
fungi often cause heart rots and produce basidiocarps on the trunk, or less frequently on
the trees larger limbs. One such infection is illustrated below.
Mazzer—Geauga Park District tree disease study, 2009
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Northern tooth fungus on native maple:
(Photo credit: permission given for anonymous use.)
In addition to our native Maple trees, several additional species have been introduced.
These trees are often seen in more developed areas near Cities, but in our climate these
trees are sometimes affected by several plant diseases. One the commonest of these nonnative maples is Norway maple. These trees are attractive, but may not be suitable for
our climate. This is because these maples are quite susceptible to two important leaf
diseases which in our area are now spreading in these trees with increasing frequency,
especially in areas that are shaded and/or in areas with high humidity (i.e., near lakes, or
rivers).
The leaves of the common Norway maple, and its bright red-leaved variety shwedleri,
may, in humid weather, be almost completely covered by two common leaf diseases in
late summer and fall, 1. By the large black blotches of the “Tar spot disease” Rhytisma
acerinum, or 2. By the chalky white “Powdery mildew” Uncinula tulasnei. Neither of
these leaf diseases causes significant problems for the trees, but both have a negative
cosmetic impact, especially when virtually all of the trees leaves on the tree are covered
by one or the other of these unsightly fungi.
Mazzer—Geauga Park District tree disease study, 2009
Tar spot on Norway maple:
Powdery mildew on Norway maple:
(Photo credits: Samuel Mazzer, 2009)
Page 42 of 50
Mazzer—Geauga Park District tree disease study, 2009
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Hippocastanaceae family: Horse-chestnut and Ohio buckeye
There are three species of Buckeye, or Horse-chestnut in Ohio, but none of them are
native to Geauga County. Numerous specimens of both the Ohio buckeye and the Horse
Chestnut have been planted in the County, but there is no evidence for the presence of
native specimens of Aesculus glabra, the Ohio buckeye, in Geauga County, Ohio. The
same can be said of Aesculus hippocastanum, the Horse Chestnut, an Asian species. Or a
third species, Aesculus octandra, the sweet or yellow Buckeye, is native to Ohio’s
southernmost Counties and would not have occurred in our area. Consequently any
species of Aesculus found in northeastern Ohio would have to be a planted specimen.
Numerous Ohio buckeye trees have been planted throughout Ohio however, so it is likely
that numerous Ohio buckeye trees, as well as other related species, have been planted in
Ohio for ornamental purposes.
The “nuts” produced by this tree, as well the nectar gathered from these trees by
honeybees, is toxic and should not be consumed by humans. As so often proves to be the
case, white tailed deer seem able to eat the twigs, leaves, and nuts of this species without
any obvious ill affects.
The Tiliacae family: The Basswood trees.
Of the four Basswood trees native to Ohio, Tilia americana is the only species common to
northeastern Ohio. Long recognized as an excellent honey plant this species was a
Beekeeper’s favorite before the current “colony collapse disorder” began decimating bees
and beekeepers livelihoods in North America. In fact, in past years, Basswood trees in
flower could be found quite easily, by simply walking through the forest during the
spring of the year. One could then quite literally “hear” the Basswood trees from the
sound produced by the thousands of Honeybees, and other nectar-feeding insects, that
would be flying around in the vicinity of these trees. Unfortunately, there are now far
fewer honeybees (and honeybee colonies) now being kept because of the mysterious
colony collapse disorder which has swept through commercial honeybee colonies.
Consequently, basswood honey is now seldom seen, (and may soon be unavailable at any
price).
Basswood trees have also been used as landscape trees, because of their generally low
upkeep and relative freedom from insect pests and tree diseases. Unfortunately, the
introduced Japanese beetle soon proved to be quite fond of the introduced “Little-leaf”
Linden (a European tree) and soon gave planted trees of this species a ragged, lace-like,
appearance. A native basswood species, Tilia heterophylla, which is a native species, is
in some ways an even more attractive tree. It is a larger tree, and possibly because the
undersides of its leaves are covered by a cottony white pubescence, it has been shown to
be little affected by Japanese Beetles. Basswood is also a preferred wood for Artists and
Wood Carvers because of its soft wood was readily carved in any direction, and is less
likely to split along the grain than virtually any other North American wood.
Mazzer—Geauga Park District tree disease study, 2009
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The Nyssacae family: Nyssa sylvatica, known as Black-gum, Sour-Gum, or Tupelo
The black gum is the only native species of the Nyssaceae occurring in the state of Ohio.
Often called Gum trees in the south, as these trees age, they occasionally developed
hollow centers and some of these hollow trees were sometimes used in pioneer times for
bee hives (often called “Bee-gums”). These hives were made by cutting a suitable
section of hollow log, and then by covering the top and bottom. These “bee gums” then
served as a primitive bee hive. While certainly not as convenient to use as a modern
Langstroff Hive, these primitive hives nevertheless served many early pioneer families
quite well in the Central to Southern states for many decades.
Although this tree flowers and produces small fleshy, but sour drupes, as indicated by the
name “sour gum”, these fruits are of no interest to humans, but a number of birds and
small mammals do eat these fruits. A unique feature of this tree is that the lateral limbs
of this tree branch off from the main trunk at a nearly 90 degree angle, which makes the
limbs of this tree very secure in regard to storm winds and especially in winter, when wet
snow and/or icing occurs. Black gum is therefore well suited for use in Parking lots,
where they not only to provide Summer shade, but because of their very secure limb
arrangement, the limbs of this tree are much less likely to break off during summer
thunderstorms or from heavy ice-loads (during winter ice storms). An additional,
attractive feature of this tree is that with the coming of autumn, few trees that can match
the brilliant reds and scarlet colors produced by the leaves of these trees.
The Cornaceae family: The Dogwoods
Only one species of Cornus reaches the size of a small tree in Northern Ohio. This
species Cornus florida, is an attractive, but short-lived tree, characterized by its beautiful
spring flowers, and its bright red fruits in autumn. These fruits are highly attractive to
birds and a number of small mammals in autumn.
Important diseases:
Unfortunately, dogwood anthracnose (Discula destructiva = Elsinoe corni) has eradicated
eastern flowering dogwood from much of its former range. We have found that this
disease is most destructive to dogwood flowers and leaves on those trees that are growing
in shaded locations. Dogwood trees growing in sunny open lawn areas often show little
in the way of diseased flowers and leaves. Other trees growing in the interior of a
hardwood forest have been severely damaged with diseased flowers, leaves and branches.
A number of dogwood trees growing in the interior of a relatively dense stand of young
hardwoods have already died. Along roadsides, where some sunlight reaches the
dogwoods leaves and flowers, it was not uncommon to see dogwood trees with their
lower leaves and branches blighted (or, in some cases, already dead) while the upper
parts of these same trees were often much less affected and sometimes even retained a
few flowers.
Mazzer—Geauga Park District tree disease study, 2009
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The same relationship was found in the relationship of the twigs of the dogwoods to the
presence of disease lesions. Dogwood trees growing in open sunny locations retained
much less damage from Dogwood anthracnose than the twigs and lower branches of
plants growing in shaded locations. We also noted that in city environments, we found a
number of flowering dogwoods growing in open, sunny areas, surrounded by mown grass
lawns did not have any noticeable lesions on the leaves or flowers.
On a trip to Norfolk, Virginia, during the last week of April, I noticed the same
relationship between humidity and relative freedom from disease on the Dogwoods along
the sides of the highway. Where the dogwoods were heavily shaded there were fewer
pure white flowers (i.e. the flowers had small pinkish-brown spots on them, typical of
Discula destructive infections) where the trees were in the open with abundant sunlight,
the flowers were pure white.
Within the Geauga Park District, I believe the dogwoods in shaded woodland interiors
will probably succumb to dogwood anthracnose over time. Those dogwoods along the
roadsides that are receiving direct sunlight during part of the day will probably survive
for some time, perhaps for years, as I noticed relatively few twig lesions on those plants.
Finally, for those dogwoods on that are still alive in some shaded woodland interiors, I
believe these plants will succumb in the next year or two.
If dogwood shrubs with flowers are desired, healthy flowering dogwood shrubs should be
planted in open, “park-like” areas consisting of close-mown lawn grasses, where they
will receive direct sunlight from early morning (to dry up any overnight dew quickly)
until late evening. The more sunlight the plant receives the better.
The USDA is working on finding resistance in dogwoods from natural sources and is
having some success, but nursery releases of these selections may not be available for
some time.
Mazzer—Geauga Park District tree disease study, 2009
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A characteristic of anthracnose-infected dogwoods is destruction of lower limbs and
branches, gradually moving up the tree (left). Leaves of an infected dogwood (right):
(Photo credits: above left—Robert L. Anderson, USDA Forest Service, Bugwood.org; right—Mary Ann
Hansen, Virginia Polytechnic Inst. & State University, Bugwood.org).
Magenta spots with tan centers characterize flowers of anthracnose-infected dogwoods:
(Photo credits: above left--Robert L. Anderson, USDA Forest Service, Bugwood.org; above right—Chris
Slaybaugh 2009).
Mazzer—Geauga Park District tree disease study, 2009
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The Ericaceae family: Rhododendrons, Azaleas and Blueberries
During this study, we did not observe any of Ohio’s Native Azalea (Rhododendron)
species. Azaleas are often planted as ornamentals around Homes and Buildings, where
they typically require additions to the soil to improve drainage and to make the soil more
acidic. Many of these plants may be poisoned by additions of nitrate nitrogen as fertilizer,
as these plants typically use only Ammonia salts or organic forms of Nitrogen.
Only larger species of Blueberries and Huckleberries are included in this report—that is,
those that typically grow to one meter or more in height.
High bush blueberry, Vaccinium corymbosum , This plant is the largest of our wild
blueberries and was the original source of Blueberries in Commerce. The Commercial
blueberry was actually a wild blueberry selected in New Jersey in 1911. This berry is
named “Rubel” and it is still a popular variety in commercial markets today. Since then,
Many blueberries have been crossed to produce berries with different characteristics for
different markets. The smaller blueberries frequently used in cooking are not from bogs,
but from sandy flatlands in the northern parts of New England , and the upper (northern
part) of the States in The Great Lakes areas.
The Deerberry, Vaccinium stamineum, this is one of our largest upland Blueberries and
can be found in scattered locations on dry uplands under White and Red Oaks, on
relatively dry sandy soils over sandstone bedrock. It is eaten as its name implies by deer,
but was also used as a food by Native Americans (its alternate name was Squaw
Huckleberry (but it is not a Huckleberry) before the arrival of the white Europeans. This
species like the Deerberry, tends to grow on relatively dry sandy uplands under mixed
oak sandy soil over sandstone, with a mixture of other upland tree species
The black huckleberry, Gaylussacia baccata, is, like the deerberry, a waist-high shrub
grows on relatively dry uplands on sandy soil, usually above sandstone bedrock. A
unique feature of this plant is that the undersides of leaves are covered with tiny honey
colored resin dots. The berries are very seedy and thus nearly inedible.
The Oleaceae family: White, green, and black Ash
In Ohio’s drier upland forests, there was once an abundance of White Ash, Fraxinus
americana. Green ash, Fraxinus pennsylvanica tends to be more common in lowlands
areas and river flats. Black Ash, Fraxinus nigra like most ash species tends to shade
intolerant, but this species is very tolerant of wet soil, and can grow in standing water for
weeks at a time. The Red ash is essentially a green ash with pubescence. These trees are
common in northwestern Ohio, where the soil contains much higher lime content than in
northeastern Ohio.
Mazzer—Geauga Park District tree disease study, 2009
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Important Diseases:
Ash Decline (now thought to be due to a Phytoplasma disease) which weakens these
trees, is now being compounded by the arrival of recently introduced wood boring beetle,
the Emerald Ash Borer. This beetle is a serious threat that may result in severe declines in
the number of Ash trees in eastern North American. In addition to these threats to Ash
trees, the
The recent arrival of a considerably larger beetle, which attacks several species of
hardwoods, including Ash trees, has recently been reported from several North Eastern
States. This beetle, The Asian Longhorned Beetle grows to be from ¾ to 1 ½ inches
long, and if it becomes established in the United States may soon become an even more
important threat to our forests than the Emerald Ash Borer. The combined assault on our
Ash trees by both insect injury and disease means that we may soon be facing severe
declines in both the number and in the overall distribution of North American ash trees.
It is now too late, but we should be remember that none of these foreign tree diseases
and/or forest insects would have been introduced into North America if shipments of
foreign raw wood products had consisted instead of Kiln dried timber, precut to square or
rectangular dimensions. Such pre-cut timber would stack into a much smaller area on
board ship than whole logs, and as a result more usable timber would have required less
space when shipped or, more usable timber could have been shipped in the same area.
And Kiln-dried, dimensional lumber would produce much less end-use waste during the
manufacture of product. And More to the point, kiln-dried hardwood would have killed
insects like the Emerald Ash Borer insects before they were transported into this country.
Bignoniacae family: Northern catalpa and trumpet-creeper vine
Only one species of Catalpa commonly found in northern Ohio, The Northern Catalpa,
Catalpa speciosa. This species is often found along the flood plains of some of our
larger rivers in Ohio. Where it can be easily recognized by its large, simple leaves, its
unusual seed pods (one common name for this species is the “Cigar-tree”) and its large,
ornamental clusters of white flowers.
An unusual characteristic of this tree is that its relatively light weight wood is quite
resistant to decay, and has been frequently used for fence posts in the past. Most of the
diseases that affect this species are rather mild leaf disorders of little consequence. These
trees are occasionally infected by a more serious trunk disease, Verticillium wilt. This is
a fungus that enters the trunk of the tree, usually by means of an injury (an infection
court) and as the fungus grows, it interferes with the uptake and transport of water
through the tree trunk. This disease, as indicated by its name, interferes with the uptake
and translocation of water, causing wilt symptoms especially during the summer and/or.
Mazzer—Geauga Park District tree disease study, 2009
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The Rubiacae family: Buttonbush
Our Native Buttonbush, Cephalanthus occidentalis , is a truly aquatic species, usually
found along the margins of depositional mucky shorelines of lakes, ponds, river
backwaters, and swamp margins. Few animals other than beaver seem to feed on this
species. Muskrats often use the bases of this aquatic shrub to help support a portion of
their winter lodges, but other than few other mammals make use this plant.
One of the unique characteristics of this species is that this is one the very few woody
plants that often produces three leaves at a node. The flowers of this plant are pure white
which contrasts strongly with the usual dark green of the leaves the round seed capsule of
this plant.
The Caprifoliaceae family: Honeysuckles, viburnums, and elderberries
The Genus Lonicera, the honeysuckles: Because of numerous introductions these
shrubs are now very common in many locations. Both Native and Eurasian species tend
to both produce colorful flowers and may also have fruits of several different colors.
Unfortunately, today there are now many different species and hybrids in the fields and
fence rows. Unfortunately children are sometimes attracted to these colorful American,
Eurasian, and Japanese species either to suck the nectar from the flowers, or later in the
year to sometimes eat the berries of these shrubs. This presents a problem, because many
of the fruits produced by the Eurasian species are toxic. In general because so many of
these plants are hybrids, none of the bright colored fleshy berries from these plants
should be eaten, nor should the black fruits of the Japanese honeysuckle be consumed.
In fact so many different species have been imported because of their abundant flowers
and colorful fruits that these plants are now a major “weed” problem. And this is in fact
Due to the abundant production of colorful fruits that these plants have spread so widely
through the Country. Unfortunately, these non-native plants are now having the effect of
large over grown weeds, by crowding out many of our native plants species.
The genus Viburnum:
Several of these shrubs are important food plants for birds and mammals in Ohio. All of
these plants produce fleshy fruits usually in the later part of the year. In terms of their
value to birds and mammals the following are among the more important:
Viburnum trilobum - Highbush-cranberry,
Viburnum acerifolium- Maple-leaved Viburnum
Viburnum prunifolium-Black-haw
Viburnum lentago- Nannyberry
Viburnum dentatum -Arrowood
Sambucus canadensis-Common Elderberry
Sambucus pubens- Red-Berried Elder
Mazzer—Geauga Park District tree disease study, 2009
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These are all late season fleshy fruits that are especially important for migratory birds and
and also supply high calorie foods for mammals. Many of these fruits are also eaten by
humans, but don’t make the mistake of eating the introduced Viburnum opulus, the
European Cranberry-Bush, mistaking them for the native species Viburnum trilobum .
The two plants look somewhat alike, but while the American species is often used for
jellies, but most people that have eaten several fruits of the European species quickly
discover that they taste so bad that the fruits of the European species are virtually
inedible, and most rather wish they hadn’t tasted them at all.